


Roadmap

by SilentWaves



Category: Dr. STONE (Manga)
Genre: Denial of Feelings, F/M, Falling In Love, Getting Together, I just love yuzu a lot ok, Introspection, M/M, Yuzuriha is a Bro, that's a pretty good tag guys listen-, the yuzuriha/taiju is background, this is just senku realizing his feelings in 9k words, why are there two 'u's in the senku tag I'm very confused
Language: English
Status: Completed
Published: 2020-04-28
Updated: 2020-04-28
Packaged: 2021-03-02 01:51:28
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 9,579
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23886943
Author URL: https://archiveofourown.org/users/SilentWaves/pseuds/SilentWaves
Summary: Ishigami Senku's six-step program for falling in love (and also getting a boyfriend in the process).
Relationships: Asagiri Gen/Ishigami Senkuu, Ogawa Yuzuriha/Ooki Taiju
Comments: 32
Kudos: 315





	Roadmap

**Author's Note:**

> guys guys listen: sengen is cute

Falling in love with Asagiri Gen was a gradual process. It took Senku a year of new emotions, a war, and his friends forcing him to take a week-long vacation for him to realize it.

* * *

**Step 1: Get enough free time to stew in your emotions**

The war was finally over. It wasn’t _over_ over, of course, since Tsukasa had barely been Senku’s friend for a minute before he got fatally wounded and had to subsequently be put into a freezer.

He can’t worry about that though, because there’s nothing more that Senku could do. The fridge was clearly in perfect functioning order, and Mirai wouldn’t hesitant even a millisecond to alert him if something was off.

What was more pressing was the need to build a ship. Even with Ryusui now on his team of science, Senku knew that professionals in the modern world could take years to build a ship the size that they need.

As Senku was stressing (only slightly, he assures himself, though the bags under his eyes and the usual composure gone from his stance indicating otherwise), the others took notice. 

Kohaku, of course, with her titan-sized heart and equally powerful eyesight, could have spotted something wrong from a mile away, which she did. Literally, to nobody’s surprise.

So Senku is currently under orders from the strongest member of the Kingdom of Science (who isn’t locked away or frozen) to relax. Easy enough. Sure. 10 billion percent, and whatnot.

He knows that it’s logical. He can’t do much anyways, since he’s drawn the blueprints to perfection, and introduced all the heavy-lifting pulleys that the children were now assembling. His being around the boat was only causing him unhealthy amounts of stress, at least according to Gen, and nobody was going to argue with the human-psychology expert on their team.

Senku’s always thought that he was good at maintaining his composure, especially since everyone was relying on his cold logic and intelligence. But, he reasons, this one time could be excused since the _life_ of his _newfound friend_ depended on this being done as soon as possible. The fridge was a good temporary situation, but it was never safe to leave such an untested lab going for too long, and Senku wasn’t sure how long the fridge would hold out for.

Regardless, he’s stuck project-less for the first time in millenia. The future of humanity doesn’t rely on his revival or the counting of the seconds to track time. His fellow villagemen aren’t relying on his inventions to stay alive. His friends’ lives are no longer in imminent danger. Well, except for one, but he concludes that thinking about it won’t do anything to help, so he opts to temporarily forget Tsukasa (though _deciding_ to forget something didn’t necessarily mean he could _do_ it).

So here he is, laying down at a reasonable hour due to lack of work (his circadian rhythm wouldn’t agree so easily — of course Senku knew sleeplessness would occur), and wondering how to fall asleep. He read an article once that if the human body stays still for 15 minutes it automatically falls asleep, though after thousands of years of doing nothing _but_ stay still, he finds that it’s been 42 minutes of no movement except steady calm breathing, and his mind is still stubbornly conscious.

Senku never has trouble going to sleep. He would work steadily until 1am, and then get his 7.12 hours of sleep, optimized for his own ideal REM cycles. He would always time his caffeine dosages to run out by 12:58am so that he can maintain a steady schedule without chemical interferences.

But now, at 9:52pm, Senku has gone through every trick in the book. He tried counting sheep, but then ended up more awake then before (he followed it with a mental facepalm, because what was he expecting?). Chrome was even out on a prompt expedition to restock his collection, so it’s not as though he had a roomate to talk to until Gen got back from working on the ship.

He was tempted to wait until 1am, when he would naturally shut down, and thought of exploring the caves for more minerals (but that wouldn’t work — everyone was too busy working on the boat, and Senku wasn’t about to go into a cave by himself with no idea of where the rest of the excavation team was).

There was no point in mindless experimentation, because any elements and compounds they had were too precious to be wasted on Senku’s personal projects. Though, by 10:29pm, Senku was so bored he was ready to do it anyways, and was about to get out of bed when he heard his roommate enter.

“You’re done for the day already?” Senku asks.

Gen visibly startles, since Senku was sent to get a proper night’s rest over an hour ago, and Gen was clearly not expecting another awake person in the room. “Jeez, Senku-chan! Don’t scare me like that, or you’ll have to treat a heart attack.” He smiles.

“Maybe you’re just not being attentive enough,” The corner of Senku’s mouth twitches into a teasing smile. “What happened to the paranoid Gen that I knew who wore blood bags in case he needed to fake his death?”

“That Gen disappeared when the Stone Wars ended.” Gen smiles, a little _too_ convincingly.

“Liar.”

Gen laughs, “Well, if you caught me, then maybe I _am_ losing my touch!” Though they were both aware that Gen could fool Senku any day he chooses, they were close enough friends that Senku could trust Gen not to. “So why are you still up?” Gen asks.

“Can’t sleep. Circadian rhythm, you know.” Senku answers, and Gen nods, because sleep science was a topic that he knew, or at least until Senku started talking about the hormones involved, etc. etc.

“What have you tried so far?” Gen asks. “And you haven’t re-invented caffeine yet, right?”

Senku shakes his head. “I’ve tried staying still and counting. That obviously didn’t work.”

Gen nods again. Counting still worked for him, as did lavender spray on his bed and sunflower oil on his cheeks. Senku, by contrast, has likely destroyed his nose from general exposure to formaldehyde and the like, and won’t get any aromatherapy benefits.

Well, when Gen could relate too, since when he was younger, he also had trouble sleeping, which was always easily resolved by… “Oh, I have an idea!”

“No worries. I can just go to sleep at my usual time, and work on some projects until then.” Senku begins to get up when Gen practically shoves him back onto the mattress.

“Come on, Senku.” He smirks. “Even Magma would be able to find out that the whole reason you went to bed early in the first place was because you ran out of stuff to work on.”

“Ugh, why am I rooming with a mentalist?” Senku asks playfully.

“Because I’m the coolest person here, obviously!” Gen responds with the same amount of jovialness. “And also, because I know a lullaby that could help. Your ears haven’t burst yet from all those explosions, yeah?”

“I’m only a bit deaf in my right ear.” Senku says.

“You’re kidding.”

“Nope.”

“And you haven’t made yourself a new one… why?”

“Taiju is very loud, if you haven’t noticed. Making a natural sound amplifier with our current resources would probably end with me becoming _more_ deaf.”

“Ugh, you should really take better care of yourself,” Gen says, sitting on the edge of Senku’s stone-age bed. “Though I guess that explains all the shouting.”

Senku gently shoves Gen’s shoulder in retaliation, but settles back into his sleeping position anyways. “If you’re too busy insulting me, then how are you ever going to sing that lullaby?”

Gen laughs softly, a trickling of music passing through his lips, followed by an actual tune. He knew his singing was perfect, especially since he’s been consistent utilizing his vocal abilities the past year or so in his tricks, and he’s been really good about drinking honey and resting his throat when he can. Even Senku, who has lost half an ear with the remaining not being any better recognizing good music when he hears it, can acknowledge that Gen has an amazing voice.

As Senku listens to Gen sing, he thinks of clear days and starry nights. He feels his own heart gently coax the blood through his veins, and feels the pulse from Gen’s thumb as it rests on Senku’s own. 

It’s _beautiful_ , and Senku doesn’t use that term to describe anything at all. But during the 47 seconds that he has to contemplate it before he falls asleep, he realizes just how much he values having Gen as a teammate.

Obviously, everyone in this kingdom was valued, since science makes everybody equal. But that doesn’t change that, subjectively, Senku might have a bias. 

Gen is someone who could fearlessly approach the strongest spear-wielder, mess with aforementioned wielder’s favoured weapon, and complete his deception with an unshakable smile. Gen is someone who can raise morale at the toughest of times, because the work _had_ to be done, though he would never convey urgency. Gen is someone who can convince a village to build an entire observatory for Senku, as though he saw right through him and found the thing that Senku missed most.

As Senku drifts off to deep, restful sleep, he thinks that the mentalist might be his favourite player in the survival game that is the stone world.

**Step 2 Part 1: Become physically attracted to a certain somebody (just a little, really)**

_Deltoid, biceps brachii, brachialis, teres major, triceps brachii…_

Senku could probably list every one of the muscles he was seeing, but he still finds himself losing his breath at the sight of Gen’s bare arms.

It was strange, because everyone’s arms are out basically all the time, and Gen’s muscles weren’t the most well-defined ones by even a millimeter (Kohaku and Kinrou especially were pretty jacked, not to mention Hyouga or Tsukasa). It was just that Gen’s arms were so rarely out in the open, regardless of the temperature outside.

Senku is pretty sure he’s never seem Gen’s bare arms, since he seems pretty adamant on wearing his yukata all the time (which, fair, because he needed _somewhere_ to hide all his flowers and whatever else he’s got stashed in there). By the time Gen had returned to their hut each day, Senku was too busy working on the latest re-invention to notice him undressing to his undershirt, and Gen would always have covered up for the day by the time Senku woke up.

But today, as Senku woke up significantly earlier than usual, he had found the time to brew his morning tea long before Gen woke up. It wasn’t anywhere near the level of his homemade coffee in the old world but he’s found that the custom tea and flower mix has grown on him. 

He now finds his cup going cold as he stares, slack-jawed, at the sight of his roomate’s arms.

“This is insane. 10 billion percent insane.” Senku mutters to himself as Gen begins humming while brushing his hair and restocking his pockets with tricks. “Absolute insanity.”

“Good morning, Senku-chan!” Gen says, and Senku can only nod in response out of fear of what words would form if he opened his mouth.

Senku pretends to look over at his blueprints, though there weren’t any flaws. He finds himself just a little mesmerized with the dexterity of Gen’s fingers as he gives his deck a cursory shuffle, warming up the cards and his hands in a beautifully elegant motion before he stuffs them into a nearly-invisible pocket. He finds himself spilling a bit of his carefully-crafted tea on his clothes, but it’s long cold and therefore of no consequence. 

This… was a new experience. While Senku could probably (definitely) identify every hormone pumping through his system, he also notes that he can’t do anything about it.

Obviously, he’s found Gen attractive before. But that’s a no-brainer, since his whole deception shtick is based on a convincing face and having an attractive one is a surefire way to advance in his industry (at least it was in the modern world). And just in general, Senku finds that people are good-looking enough, and that’s all there is to it. He’s never had to discuss attraction with anyone, because everyone is attractive in their own way so nobody’s physique has ever particularly stood out to him.

Besides, he considers science his first and only love. If he were to devote all his time to one thing, it would be going to space as soon as possible. A few girls and a few guys confessed to him in school, and he’s never rejected them because he had no reason to. They would always break up with him a few days later because he wasn’t dedicating enough time to them.

He later decided they just weren’t interesting enough to him. It wasn’t that they were bad or boring people, because humanity is probably one of the most interesting things on Earth next to gravity and the deep sea. They weren’t bad-looking either, because they were just about as attractive as everyone else around him. 

It might have just been that they were just that. Plain old attractive people with interests that didn’t align with own. They were people whom he could never stay together with because their hobbies didn’t interest Senku and vice versa.

He long figured out that basing a relationship on looks alone wasn’t enough data to conclude a partner and a healthy relationship.

So if he were entirely honest with himself, Senku has _no idea_ why he’s so entranced by Gen’s arms. If he were to hypothesize, it would be because this is the first time Gen’s ever looked vulnerable, no, that wasn’t it, he didn’t look vulnerable, but _exposed_. His secrets were out for the world to see because he can’t hide cheap magician’s tricks in his sleeves when he’s not wearing any.

If he were wearing his blood bags, they would be completely visible, and it’s almost like Gen’s subconscious decided to trust Senku enough to figuratively drop his weapons and hold his hands where they could be easily seen.

He counts 112 BPM, which is 34 beats faster than his resting heart rate. He has no way of measuring his blood pressure, but he’s sure it’s elevated. There’s nothing that’s triggering his flight or fight reaction, but every muscle in Senku’s body is tensed, and he finds himself being unable to tear his eyes away from Asagiri Gen until he puts on his overcoat.

_91 seconds._ That’s how long it took Senku to tear his unblinking gaze away from his friend. It’s not long enough to cause suspicion, that is, if the person he was staring at wasn’t a goddamn mentalist.

“Is something wrong? Do I have a crack scar somewhere that I missed?” Gen asks innocently.

“No—” Senku says, _much_ too fast for it to not sound suspicious. “I mean—” For once, he’s at a loss for words. It’s even worse when he sees a tell-tale grin on Gen’s face, because it’s too amusing for him to conceal it.

“Don’t worry about it. I guess that’s just what a well-rested Senku looks like.” Gen doesn’t press the issue, though the glint in his eye sends a very clear message that he is _not_ about to let this go. “I’m going to work now. Ginrou is already looking a little worse for wear, and I’ve got just the thing to get his work ethic back up!”

He begins to step out the door, and Senku was in the process of taking deep, meditative breaths to regulate his body back into homeostasis when Gen pokes his head back into their hut. “One last thing, dear Senku, would you like to make some more ramen today? Francois is out for the week to inspect the farming yield, and we haven’t had any good food for a while.” He speaks as though it was completely unrelated to his previous point, though Senku knew better. He wasn’t in any state to object though, so he nods and makes a mental note to go foxtail collecting today.

“Well then, have fun relaxing!” Gen does a little wave, and leaves with a smile on his face.

Senku takes another 16 deep breaths before he can think clearly again. “What the hell was that…?” 

He goes to the foxtail field, and deliberates on his morning attitude as he collects the plants.

He makes a list of potential suspects. Gen himself is at the very top of it.

“He definitely pulled some cheap mentalist trick while singing me to sleep.” Senku says to himself, deep in thought. “Subtle manipulation hidden in his notes, or the words, or something.” He hums in thought. “Hypnosis, even. I’m sure a mentalist like him is capable of such a thing.”

But he knew it wasn’t that, though Senku doesn’t want to admit it.

It was completely possible that it was just human physical urges, since Senku has time to himself for the first time in 18 years that wasn’t occupied with thoughts of science. Now that he has available space in his brain, it was likely that it decided to shoot him with the hormones that he’s been putting aside for so long.

But it was more than that, maybe. No. Senku would not admit that it was more than that. It was simple horniness for sure; he sees it in everyone else in the village. Taiju and Yuzuriha, for one, and Senku _10 billion percent_ was not about to think about them… nope. Senku wasn’t even going to finish that thought. But it was possible. And it was evident. The looks they give each other sometimes… and no, Senku didn’t even have a millimeter of interest in continuing that train of thought. 

So based on his totally unscientific sample data of exactly three people, he can conclude that the relief of surviving this long in the stone world was enough to send anyone’s brain into a frenzy. Probably. Small sample sizes weren’t exactly proper experiment procedure.

But that is definitely all there is. Senku is not thinking of ~~all those times~~ the one time that he found Gen outstanding in a 10-billion-percent-attractive kind of way, because that was a vulnerable situation. Anyone would have had a split second thought about dating or kissing or hand-holding or ~~oh god no he was _definitely not_ thinking about marriage~~ if they were gifted an observatory.

Anyways, the whole village is stressed about Tsukasa, the boat, and the exploration, so it’s natural that the body would provide a healthy way to relive it.

There was nothing going on. Senku was not thinking about how comforting Gen’s arms would feel around him. Senku was not thinking about how soft Gen’s hair probably is with the natural treatments he’s been giving it. He is _definitely_ not thinking about those dextrous fingers.

Logically, there is a scientific answer to what he’s experiencing. But if there was nothing more to it, Senku would feel a lot more relaxed.

**Step 2 Part 2: ~~Become emotionally attracted to a certain somebody~~ no no that is not what’s happening here**

Senku’s mind, which is usually such a valuable asset, has decided on betraying its owner this very day.

Senku didn’t _want_ to be suddenly considering romantic prospects at this time, especially not when a whole village of people are trying to save their former enemy for his sake. 

He also didn’t think he was so starved for intimacy (which he wasn’t, but really, it’s not _his_ fault everyone assumes he doesn’t like human contact) that he’d begin acting like a stereotypical teenager as soon as he has few more than 2 seconds to relax.

But at least this was all it was, Senku tries to reason with himself, though the sheer amount of time he’s spent trying to convince himself of this fact only serves to prove it wrong. But it doesn’t. But it does. Ugh, for once, Senku wants his brain to take a break for a minute. He never thought he would fall into the ‘mad scientist’ trope, despite his friends’ jokes, but he’s reconsidering that now.

Maybe he could listen to music, that was always good for when he was stuck on a particularly difficult problem. Obviously, he can’t do that now since he doesn’t have the tracks or CDs (building a music player shouldn’t be a problem though), but he could probably remember the tunes to whatever was on the radio before the petrification. 

No matter what he began humming though, it would all turn into the lullaby that Gen was singing to him last night (though not nearly as well-sung, since Senku didn’t hesitate to admit that he was pretty tone deaf, even without the damaged ear). He was beginning to reconsider that whole hypnosis theory.

Senku sighs as he walks back to the village, basket full of foxtails. He’s going to have to find some villagers who wouldn’t mind doing extra work, or at least some villagers who weren’t too run down from the main project.

After dropping his basket of foxtails in his laboratory, be ventures to where the ship was in the process of being constructed. Maybe it’s because Senku is looking for some work, but he figures Kohaku can’t wrestle him back to his house if he’s just making sure all the pulleys are running smoothly.

“Senku? Why are you here?” Kinrou asks when Senku gets to the ship. “I thought we told you to relax.”

“Yeah, we’ve totally got everyone covered here,” Ginrou says from his nice grassy spot in the shade. “You don’t need to worry about a thing.”

“Hmm.” Senku looks around. “I figured I should come by to make sure all the machines are working alright. How’s the heating system? Do we have proper smoke escape routes? What about—”

“Senku!” Kohaku shouts from across the deck, and launches herself right in front of Senku in the half-second it took him to blink. “Gen told me to watch out for you today, and of course he was right, as he always is when it comes to you.”

“He’s our only mentalist. We can’t expect any less.” Senku points out. “And I’m just here to check on the machinery, because we really should regularly grease the pulleys so that they can consistently run—”

“We have all the blueprints for that, Senku!” Kohaku interrupts, face scrunched up in concern. “You’ve worked yourself to the bone lately, and you know you’re not effective at all unless you’re well rested enough to think clearly.” Kohaku gestures to Kaseki and Yuzuriha, who were presenting their work with stars in their eyes.

“Well, I supposed then you’re all familiar with the coefficients of friction for every surface here?” Senku asks sarcastically. Kohaku doesn’t have an answer, but resolves to follow Senku around as he surveys the boat to make sure he doesn’t get carried away.

Senku was inspecting a ramp with a too-high slope when he heard Gen enter the room. He makes a note to wonder why he could recognize Gen’s footprints when there were over 100 people in his workforce. It was probably because he was one of the only bare-footed ones, he reasons. 

“Kohaku!” Gen shouts. “Didn’t I tell you to look out for Senku so that he _doesn’t_ end up on the boat?”

“Not my fault. I don’t like it either, but you can’t argue with the numbers.” Kohaku sighs. “Unfortunately, Chrome is out getting more rocks or something and he’s the only one to know about the ‘whatevers of fiction’.”

“Coefficients of friction,” Senku corrects.

“We could wait for Chrome to get back,” Gen narrows his eyes.

“We could also split the workload to make sure Chrome doesn’t burn out.” Senku says while shaving off the end of the wood.

“That’s what we’re trying to do for _you_ , idiot.” Kohaku says. 

“I don’t burn out,” Senku says. “There’s no precedent.”

“Just because it’s taken you your whole life to tire yourself out, it doesn’t mean it won’t happen.” Gen says. “Don’t even _try_ to argue with me on psychology and mental health, Senku. You’re smarter than that.”

Senku looks up for the first time since he’s started working on the ramp. Gen was serious this time, and the stern look in Gen’s eye indicated that he would not hesitate to resort to less honest means of convincing Senku into relaxing if he had to. “Sure. I’ll just start on that ramen. You guys aren’t using any batteries right now, right?”

Kohaku shakes her head no as Gen drags Senku out back to the village. 

Senku… is at a loss for words. He was so used to Gen’s paper-thin facade of being a carefree leech that seeing such raw emotion had him shocked. He’s barely even processed the hand tugging at Senku’s sleeve (although they were long gone from the ship by now), and how warm it felt.

Sure, he knew that Gen was capable of being terrifyingly convincing — he was there when Hyouga’s spear broke, and when he nearly died to Magma, and a couple other times too — but he’s never had Gen’s unavoidable attack directed towards _him_ before. “I left the foxtails back at our hut, so I hope that’s where you’re taking me.” Senku says, as nonchalantly as possible. He doesn't point out Gen’s hand on his arm though, because Senku doesn’t mind the contact.

“Yes. We’re going to sit you down at home, and if you’re _really_ desperate to work, we’ll sit you down with Mirai and have you two make ramen together.” Gen says, tone a bit softer now, and his pace much less hurried. 

_Of course Gen would have such a steady control on his emotions_ Senku thinks, with… was that affection? He hopes it’s not affection. If it is, it’s probably just platonic affection, like how he feels when Taiju accomplishes another inhuman task or when Yuzuriha pieces together another human statue. His brain, the traitor that it is, says differently.

“Oh yeah,” Gen thinks for a second. “Mirai and Suika went tree planting since we’ve been cutting so much down. There’s probably some other kids around though, and we can teach them how to make ramen while we’re at it.”

“Two birds, one stone.” Senku agrees. As a bit of morbid humour, the moderners started to use more stone-related idioms whenever they could. It hasn’t started getting old yet, at the very least. “But aren’t they working on batteries right now?”

“We’ve already created waaay more batteries than we could ever need.” Gen shudders at the memory of wrapping all those manganese batteries. He seems like he’s back to normal now, but Senku doesn’t miss how his eyes are filled with more fire than usual.

Later, as the workers greet them with tired eyes and sore muscles, Gen brings over the freshly made ramen and watches with Senku as their friends eagerly gulp down the reward for their steady labour.

“Senku-chan,” Gen takes his newly-acquired chopsticks and picks out his least favourite parts of the dish, eating them first so that the remainder is only what he enjoys. “I hate to say this, but I think I’m getting used to the stone age food.”

Senku laughs, “Same. It’s great that we have Francois now to cook us real food, but I think my palate evolved within the past year to favour _foxtail-ramen_ , of all things.”

“When they come back from inspecting the farms for quality, we should ask them to make us real ramen.” Gen says. “Obviously, we’d have to find someone to gather the ingredients first.”

Senku grins. “That’s a mentalist for you.”

“Wha— Hey, what’s that supposed to mean?” Gen crosses his arms in mock-outrage.

“You always go straight to getting someone else to do it, but isn’t there more satisfaction in getting it done yourself?”

“Says the one who’s making machines _specifically_ so that others don’t have to do all the work themselves.” Gen sticks out his tongue playfully. “Though the machines themselves are much more work than they should be.”

“Well that’s the point. We still made that machine as a tool for future advancements.” Senku slurps at his noodles. “It still counts as our own work.”

“Ugh, Senku,” Gen says, dragging out the last syllable in Senku’s name. “We just finished a day of work, so let’s just relax a bit more.”

“You’re just saying that because I won.” Senku smirks.

“Lies,” Gen says smoothly. “You made your point that science is a lot of manual abour-lay and doesn’t involve any cute harems. Hardly a win, really.”

“A society would _not_ function well if everyone had a harem. You know this.”

“But then just one for me.” Gen winks.

“If you want a harem you’ll have to build it yourself. We could probably make a stone age version of an android.”

Gen playfully punches Senku’s shoulder. “I could find _real_ people to join, you know.”

“Is that an invitation?” Senku did not mean for the thought to slip out of his mouth. Hell, it wasn’t even supposed to get all the way around the synapses in his brain, much less the ones at his vocal chords.

Gen merely laughs as a response, because he can read a situation and could probably tell how Senku regretted the words as soon as they were were spoken. And because Gen paints himself as good-friend-material, he shrugs it off with a light retort, and they continue eating their ramen in comfortable silence.

Senku, however, felt his face go flush, but not with the heat of the broth. 

_This better not be attraction,_ Senku thinks, because if it is, then the solution to it would be a lot more complicated than the one for simple carnal desires. 

Senku, as a general rule, doesn’t like to deal with matters of the heart too much. So having his own betray him like this with the rapid beating and the extra blood being sent to his face was a new experience, and not one that Senku could say he entirely disliked.

**Step 3: Mix the two halves of step 2 (and spiral into a panic)**

_He’s pretty amazing, isn’t he?_ Senku thought while laying down on his make-shift mattress. _He has all this knowledge on psychology — like my own on science. It just goes to prove how dedicated he is to his craft._

And Senku was laying awake at 1272 seconds past midnight, thinking about his roomate whose soft snoring could be heard in the otherwise silent night air. 

He figures that there was no denying the inevitable. Sure, he might have just a _little_ crush on Gen. That’s fine. It’s not that he hasn’t experienced romance before, he’s dated a few people in the past (but it was never _serious_ was the completely uncalled-for response from his brain. 

It’s just that he never connected with them nor found the need to compromise his Very Important Science Time for a small dinner or the newest movie. Not that Gen would ever force Senku to lose time doing what he loved, he knew. He would only stop him if it ever begun affecting his well-being and overall health (which, Senku has to admit, is what’s happening right now).

But Senku finds that he _wants_ to spend time with Gen. He wants to stargaze with him more and listen as he tells him about his observations on other people. He wants to talk with him about their respective fields of science late into the night because they’re both masters of their craft and genuinely interested in learning more.

He obviously wants to go to the moon more, but now he’s wondering if Gen would like to come with him. 

Senku audibly smacks his own head at this (and _ow_ , he accidentally hit where the scar made his skin tender to the touch), because he can’t even tell Gen’s true intentions half the time, how the hell is he supposed to know whether he actually cares about Senku enough to leave Earth with him?

_But is that really all?_ a small voice in Senku’s head decides to ask. _Wasn’t it Gen who got the villagers to build you your own observatory? Wasn’t it him who saw the engraving you made into the tree? Wasn’t it him who broke Hyouga’s spear and saved everyone’s lives? Sure, he’s definitely one damn good mentalist, but he’s also 10 billion percent on the Kingdom of Science’s side._

And it’s true, because even the best mentalist couldn’t fake the joy in Gen’s eyes as he watched the lightbulb light up. Even the greatest actor in the world wouldn’t be able to put on the smile that Gen had while he drank his Cola. 

And Senku can guarantee without even a millimeter of doubt that not one liar, no matter how experienced or how skilled, would be able to willingly say they’d fall into hell so easily. 

Senku’s known for a while that his friendship with Gen was ~~a little~~ a lot different from his friendship with Yuzuriha and Taiju. With them, it was like spending time with what he pictured having siblings to be like (though obviously those two somehow wouldn’t be related in this scenario because, ew, incest). But with Gen, it was just a sense of… well, the best way Senku could describe it would be to compare it to an experiment where the result was perfect and nothing went wrong in the process. It was what happens when two reactants achieve perfect equilibrium. It was when sparks fly from a newly-perfected fuel formula but with a guarantee that no harm is to accompany it.

Working on inventions with Gen was like flying without the threat of storms. Laughing with him was like an electric shock without the pain. Plotting with him made Senku feel like he was running a marathon without ever getting out of breath.

He knows it’s all just a side effect of the adrenaline, dopamine, serotonin, etc., but he could never pinpoint the exact source like he usually could. And with Gen, it felt less like the overwhelming ocean of exhilaration at seeing an invention work as it should, but instead like a steady stream of a pleasant buzz. 

Ever since he was younger, Senku knew what he wanted from a relationship. He picked out the books from all the leading professors of psychology at the time when he got asked out by a nice-enough boy from his class. 

His young, impressionable self at the time thought that relationships were based on looks, and because everyone has their own unique appeal, Senku had no reason to reject him. 

Senku figured out all the tricks: effective communication, compromise, mutual respect, etc. but their relationship only lasted two hours after their first date when Senku invited him to build a model Wright Plane (to learn from the original source and how it developed) and the boy promptly stomped away because he thought they were going to the park.

He didn’t think too much of it, because even at a young age Senku knew he didn’t want to even be _acquaintances_ with anyone who didn’t respect his interests and didn’t have interests that Senku was enthusiastic about. Mutual give and take, and all that.

There was a girl in junior high who was the next person to ask him out. They had a nice night together watching Doraemon, but then she admitted that there was just no ‘spark’. Senku didn’t have any complaints, though they still got together for regular Doraemon marathons afterwards (first weekend of every month). _Huh. Wonder if we can dig her up someday._

That was about the extent of his relationship experience, because he didn’t care too much about finding ‘the one’ when he was so occupied with the desire to go to space. Anyways, it seemed like too much trouble to find a relationship with a perfect amount of give and take from both parties, where each person has enough to give without an abject desire to overtake the other’s life.

But Gen, _Asagiri Gen_ , was an enigma. He was the outlier, the exception, the… whatever other synonyms there are — Senku’s not the master of words in this Kingdom, and he doesn’t plan on becoming one. 

Gen knew psychology better than anyone, and Senku could spot when his facade was up well enough by now. There would never be an opportunity for them to miscommunicate, theoretically. They already show an interest for learning about each others’ passions, and understand each other enough to know that they can’t ever monopolize the others’ time. 

Obviously, if they were ever to be in a relationship, Senku doesn’t doubt that they’d disagree sometimes. There’d be moments where Senku gets tired of Gen’s insistance of keeping up his ‘scumbag’ mask, and moments where Gen in turn gets tired of Senku’s long-winded explanations. 

But he also doesn’t have a millimeter of doubt that they would care and respect for each other enough that when disagreements happen they would find a way to compromise and move on. And— 

_Holy shit, please stop there,_ because Senku was already thinking of them getting together when he _hasn’t even confessed_ and this is bullshit, he should be asleep, he’s getting so carried away with this.

He looks over at Gen anyways, his skin shining in the moonlight.

Senku lets out a loud sigh, not caring about making too much noise since Gen should be reaching the natural deep sleep progression of REM now, though he can never be too sure what Gen’s trained himself to do. Maybe the guy figured out how to survive on light sleep alone… who knows.

But Senku, despite everyone’s clamouring about his getting to sleep earlier and finally fixing his schedule to that of the villagers’ (which was unsurprisingly set to follow the sun), knew his own rhythm wouldn’t work like that. He’s been awake for 2748 seconds past midnight now, and he’s assuming that in approximately 852 seconds he’ll naturally go to sleep, as per the previous schedule.

Besides, Senku wasn’t sure if he was mentally prepared to face Gen’s arms again, and would rather be asleep during that time.

**Step 4: This better not affect Senku’s ability to help his friends’ developing relationship**

****

At this point, Senku realizes that there's no more point in denying it. He may or not ~~be in love~~ have a very slight crush on Gen, and it’s fine, because nothing is going to come out of it. 

He’s going to keep relaxing this week because Kohaku would kill him otherwise, and afterwards he’ll settle right back into his old routine, watching over the crops and helping with any new inventions that the village needs. 

And he’s practically bursting at the seams to get working on that ship. His own design (well, it’s more of a collaboration with Ryusui), sailing the seas and exploring the world. A full-sized model, guaranteed to work simply because Senku knows how capable the workers are.

Speaking of, Senku could find the logic behind Kohaku’s forced break on him. Other than the slightly terrifying prospect of being in love, Senku found the time to connect with some of the other people in the village. 

After wasting his second day of vacation on figuring out his own emotions, he decides to just relax for the remainder. 

So on the third day, Senku and some of the children built a board and game pieces to give Ryusui a break by playing Monopoly. It was going great until Ryusui decided to use real Dragos, and Senku was left going back to Yuzuriha to ask if she could sell some more clothes.

The third was spent glueing statues back together to pay Yuzuriha back. Kohaku would probably consider this work, and therefore prohibited to Senku, but she decided that working off a debt didn’t count.

Honestly, it was nice. All he had to do was group the pieces into similar looking limbs, and Yuzuriha would do the rest. They talked about whatever, catching up after a year apart, and watched as Yoh struggled with all the crumbling statues. 

So they kept up the schedule, with Senku coming in with a newly-made batch of glue and topics to talk about. And Yuzuriha would have brought more fabric in case she gets an idea for an outfit (which she would then proceed to sew in an average of 11.92 seconds)

It was the last day of Senku’s vacation when Yuzuriha decided to essentially drop a nuclear bomb into their conversation.

“So I’m thinking of asking Taiju out,” Yuzuriha says.

Senku stops what he’s doing, dropping the stone fragment as soon as the words were spoken. He opens his mouth to respond, and then closes it again. Takes a deep breath. Lets it out. He opens his mouth again.

“Senku? Is something wrong?” Yuzuriha asks.

“Ah, no. Not at all,” Senku rushes. “I’m happy for you, congratulations on the wedding—”

Yuzuriha smacks Senku on the arm then leans back into her chair. “Oh, shut up,” she says playfully. “I thought you already knew I liked him.”

“Yeah, yes. I know that.” Senku nods. He’s always known that his friends had been dumbly pining after each other since they were children, but it’s never occurred to him that they would actually _get together_. 

No, that’s a lie. He’s already got an idea of what he’d to at their wedding to spice up the reception a bit (3% hydrogen peroxide solution, yeast, and warm water, but that might be too basic), he just doesn’t know how to advise their relationship since he’s become _biased_ now.

He mentally knocks himself in the head, because _of course_ this infatuation couldn’t wait until _after_ he’s gotten his best friends into a nice comfortable relationship rhythm. 

What if they ask him for an ideal date and he blurts out “observatory”? What is Senku going to do when they ask him what gifts they should give the other and he responds with “cola” or “a psychology journal” or “some goddamn shoes, seriously”.

He should let them know. They can’t keep confiding in him anymore, he’s an unreliable source of information and he _10 billion percent_ doesn’t want their potentially wonderful relationship to be ruined because Senku couldn’t keep his own personal opinions under control.

“Um, Senku?” Yuzuriha taps his shoulder. “You’ve been quiet, and you’re frowning… Does the idea of me liking him… Do you not like it?”

“What? No. Absolutely not.”

Yuzuriha sighs a breath of relief. “Well that’s good. I didn’t think I could be friends with someone who didn’t support me.”

“Well, obviously, you two would be perfect for each other. You _are_ perfect for each other, since you’re both overly-sentimental oafs.”

“Sorry, are these emotions too much for you robot brain?” She teases. “If that’s the case, sucks to suck, you dumb genius.”

“That’s an oxymoron.”

“Oo, picking up some fancy words from Gen now?” Yuzuriha shakes her head. “That’s no good; half of your charm comes from how _un_ pretentious you sound.”

He shoves her gently, laughing. “It’s barely pretentious.” Yuzuriha shakes her head in protest, a large smile on her face.

“But anyways,” Her facial expression drops back to serious. “Do you think Taiju would accept my confession.”

Senku tries his absolute hardest to not laugh at the thought. “You really think he doesn’t see you in a romantic light?” He says when he’s finally managed to shift his facial expression from ‘about to die from laughter’ to ‘mildly constipated’. 

“What if he just thinks we’re just friends?” Yuzuriha blushes in embarrassment. “Hey Senku, if you were to confess, what would you do?”

“Well logically you could just tell—” And Senku stops, because logically one _could_ just tell their object of attraction, but now that he’s experienced aforementioned affection for himself, he’s not so sure it’s that easy.

_Logically_ , it’s best to be clear and straightforward with no room for misunderstanding. But if it was Gen receiving the confession, there was room for subtlety; it could just be implied and — _Oh fuck it’s happening already._ — Taiju would sure as hell not know subtext if it smacked him in the face (proven by past experiments), and Yuzuriha would get flustered too easily to provide said subtext in the first place.

Was Senku a horrible friend now? He should know what to do, right? His friends are cheat-level amazing in their own ways, but when it came to their relationship they were such idiots he wouldn’t be surprised if —

Yuzuriha laughs. “You look frustrated again! It’s not that serious, I think I’ll just write him a letter or something.”

Senku looks up. He was overreacting, he’ll just follow Yuzuriha’s lead for this one. “A letter?”

She blushes, “Well, ok. It’s not as cheesy as it sounds, I promise. I just want to get it off of my chest in a way that I can’t mess up.”

Senku sighs. _Take yourself and Gen out of the equation for a second. It’s just Taiju and Yuzuriha. What’s next?_ “I think… you should talk to him. He still visits you before you guys go to sleep, right? Ask him out then.”

“But what if I mess up?” She gasps, as though a lightbulb just lit up inside her brain. “I should get Gen to feed me lines!”

_Goddamn it_. Just as Senku manages to eliminate Gen from him brain while thinking of relationship advice, Yuzuriha decides to bring him up again. “Well, no. It should probably be your own words or you’ll regret it.”

She hums in contemplation, and giggles a little, “look at us, gossiping about relationships like middle schoolers at a sleepover.”

“Well, despite popular belief, I _do_ have emotions and care about your happiness.”

“Ha! Joke’s on you,” She smiles. “We already knew that!”

Senku smiles back, “I’ll be honest. I don’t think I’ll be much help with your confession. But I think you should just be yourself, since that’s who Taiju fell for.”

“‘Taiju fell for’?” Yuzuriha quotes.

“Ah, shit, well, you know,” Senku stumbles. “You know? Since he’ll 10 billion percent accept your confession he probably likes you, right? Yeah. That’s it.” He may as well leave now, since he’s already spilling secrets (not that it was much of a secret to begin with). 

Senku misses the small smile on Yuzuriha’s face as she solidifies her resolve.

“Well I guess I should be — I should go.” Senku awkwardly mumbles, getting up. “Uh, good luck! Not that you need it, much less need _my_ luck of all things— ” and Senku forcibly closes his mouth, because he’s rambling and he’s never sounded less convincing in his entire life. “You’ll do fine!” He says as he runs away.

As he departs from a Yuzuriha who has just decided that tonight is the night that she’ll confess her longtime feelings, he misses how she whispers a discreet “good luck to you too, Senku.”

**Step 5: Maybe hiding your feelings doesn’t work when you’re trying to hide them from a mentalist, of all people**

This was fine.

That is, this is relatively fine in comparison to getting sucked into a black hole, or having the sun explode a few million years early. 

So it’s fine enough to be manageable, and manage it Senku will.

He takes a few deep breaths (that’s funny, his asthma hasn’t been acting up lately), was promptly distracted from his problem when Taiju announced that he and Yuzuriha were dating now (Senku would not admit to shedding a few tears of joy, but they all know it happened), and started mentally reciting handbooks on how to cover up feelings (not that it would ever work, especially not on Gen).

Senku’s never had any problems with romance before, and just because his dad was never any good at keeping a relationship doesn’t mean that Senku didn’t have any point of reference (that’s a lie and he knows it).

Normally, it wouldn’t be a problem. Senku never did a new experiment with a 100% certainty that it will turn out how it should, and he’s never dated Gen before, so it’s not like he has any past experience to improve upon. Even so, pupil dilation, heart rate, blood pressure, and general body language was usually enough to tell how another person felt about someone, but Senku’s problem was that Gen could both fake and hide those things.

Senku was constantly impressed by Gen’s more-than-competent skills in psychology, just as he is in Kaseki’s craftmanship ability or Taiju’s endurance. But this time, it was used against him: he would think exactly what Gen wanted him to think, there would be no secrets that Gen couldn’t hide if he wanted to.

So Senku is going into a confession blind.

That’s fine, he reasons, because at least the sun isn’t exploding. And he checks just in case, because his luck is absolute shit (it’s a good thing that his luck isn’t enough to disrupt science since it’s _wayy_ too early for the sun to even come close to exploding). 

He’s getting off track. In fact, he’d probably conclude that he’s just putting off the inevitable. Their teamwork is likely going to suffer if Senku continues to feel embarrassed around Gen. Either he gets rejected and recover in an estimated week-long period or gets accepted and has to deal with a whole new set of unknowns. The recovery time is based on the data interpolated from how it took for him to get through the five stages of grief after finding out about Byakuya’s death (42.8 days, with a 2.5 day margin or error) and freezing Tsukasa (7.2 days and counting).

But that, unfortunately, had a scientific basis. He knows his feelings enough to know how long he’d feel hurt and how soon he can recover from that. He’ll go back to his regular schedule afterwards and it’ll be like nothing happened, because nothing effectively did.

But getting accepted? Getting a boyfriend whom Senku was afraid to lose? Getting the chance to date someone incredible and amazing and skilled and beautiful and loyal and also— this should stop. He’s already gone over why Gen means so much to him, and this is just prolonging his period of panic.

Maybe he fears the prospect of romance more than the possibility of rejection.

And he figures he should enjoy this feeling of discovering something unknown. He could study his own patterns of attraction so that he’d know what to look for in others, but oh, he doesn’t really _need_ to know that though, since he’ll have Gen at his side to do any psychological analyses that they’ll need. Well, at the very least there’s no problem in having knowledge, even if there’s no important use for it at the moment.

But this wasn’t building a rocket. He was wrong before about the magnitude of it all, because this _wasn’t_ a steady flow of sparks flying through his bloodstream. No, this was an explosion. And the scariest part is that he’s not afraid to take it head on. 

Whatever happens, he wasn’t going to get hurt. Or if he does, he’s pretty sure Gen would at least let him down gently.

Speaking of, Gen probably already knows anyways and has concocted a perfect plan to reject him without Senku even asking the question. 

Senku ponders this for a second, because if he acted the exact way Gen expected him to, it would result in the least amount of pain for the both of them.

…But then, if that’s the case, why hasn’t Gen done anything yet? 

_He’s probably waiting for the right moment,_ Senku thinks, _but then why would he need that? The Gen I know would speak up (through himself or someone else) whenever he had a problem with something. Why should this time be different?_

He wasn’t afraid to call Senku on his shit whenever he pushed too hard for a ploy to get Taiju and Yuzuriha together, or whenever he was pushing the villagers too hard on a task. He has to reason to not stop Senku, who has been nervously dancing (figuratively) around him all week long. 

So why hasn’t he?

Of course, Senku comes up with 89 possibilities right away, but his mind (the goddamn traitor) could only focus on one.

It was presumptuous, it was stupid, he had no solid evidence that it was the correct conclusion, it—

**Step 6: Ah, screw it**

“I love you,” Senku says that night, nearly as soon as Gen enters the room. “I know there’s a lot of cultural context that makes the phrasing sound more serious than it really should be, but it’s the most accurate way to sum up—”

Gen starts laughing.

Senku stares for a second, registers the lack of mocking from his expression, and allows himself a hesitant smile. “And I know you already knew.”

“I’ve probably known longer than you have, but I bet that you’d confess next week,” Gen sighs good-naturedly. “You just lost me 1000 dragos to _Taiju_ of all people.”

Senku feels his muscles unclench, and feels surprised at how relaxed he feels after a week of high tension but also isn’t surprised at all because he knows all too well how skilled his conversation partner is. “We can make it back. I lost a bunch of money to Ryusui while playing Monopoly.”

“I don’t know what you were thinking, trying to beat _Ryusui_ of all people at Monopoly.” Gen shakes his head and smiles as he takes a seat on the bench, shoulders nearly brushing against Senku’s. Senku finds that he wants to shift closer.

“…So?” Senku asks. Though he’s already braced himself for every possibility, he also feels the very human desire to not have to face them. “Do you want to… date? Or whatever, if you’re not into that it’s fine with me.”

“You’re not fooling anyone like that.” Gen leans in, and Senku’s gaze probably betrayed his true intentions because his body is a traitor, because his eyes dart down to Gen’s mouth for not even a quarter of a second, barely enough for Senku to register that he did it in the first place, really. 

Gen, obviously, sees Senku’s momentary lapse and before he knows it their lips are touching.

They’re soft. And warm. And nice. Senku probably should be able to tell the exact temperature rise he just experienced or the hormones shooting through his brain, but he can only focus on Gen’s slightly flowery scent (probably from his sleeves), and the nerves that just ignited with the feeling of Gen’s breath mixing with his own, and the feeling of his hair as it runs through his fingertips — Senku didn’t even know when his hands wandered over onto Gen’s neck.

Senku, for the first time in millenia, lost count of how much time had passed.

“You haven’t answered me yet,” Senku mutters against Gen’s lips, sounding a lot less insistent than he should have been.

“You’ve always preferred people’s actions to speak for them, didn’t you?” Gen says in response, and laughs a little. “I didn’t realize I wasn’t being clear enough.”

“No I… got the message.” Senku nods, a little too stiffly. 

“But if I were to say it…” Gen meets Senku’s eyes. “I love you too, as grossly cheesy as that is.” 

Senku laughs, both relived at the admission and also frightened at what it means. “We should go to the observatory sometime.”

“I’ll talk to you as you map the stars.” Gen nods, because of course he understands. He shifts closer to Senku, as though they weren’t close enough already. “How do you feel about me resting my head on your shoulder?”

“Only if I can rest my head on your own.”

So they do. They breathe in sync as they sit on the bench, heartbeats loud and quiet at the same time. Hands intertwined, but not so much that it’s constricting. Mumbling a conversation just loud enough for the two of them to hear, about space or the science of love or whatever else is on their minds.

Senku’s sure their relationship, like every other, isn’t going to be completely smooth sailing, but he’s also sure that he’ll never have any doubt in it. As rocky or as calm as the waves are, they’re not afraid to ride them.

They’re going to be more in sync than ever — let’s see any new enemies just _try_ to stop them. They’ll stay up long enough to discuss whatever’s on their minds, and probably talk about their dreams as if the other didn’t already know everything about it. Senku’s probably going to remember every word that comes out of Gen’s mouth, and Gen will probably be able to predict Senku’s own.

And for the first time this week, Senku doesn’t disagree with his brain when it thinks that he wouldn’t have it any other way.

* * *

Falling in love with Asagiri Gen was a gradual process. It took Senku a year of new emotions, a war, and his friends forcing him to take a week-long vacation for him to realize it.

But like all roadmaps, Senku eventually reaches his goal.

**Author's Note:**

> I. love. them. 
> 
> that's it that's all I have to say also please come on Yuzuriha is Senku's childhood friend they're probably such good bros and have such a nice supportive but also sibling-like friendship?? Please I just love that idea a lot.
> 
> Anyways hmu on [Tumblr](https://voicelesswaves.tumblr.com/) if you wanna talk about sengen or Dr. STONE


End file.
